Dear visitor, welcome to SPRINKLER TALK FORUM - You Got Questions, We've Got Answers. If this is your first visit here, please read the Help. It explains how this page works. You must be registered before you can use all the page's features. Please use the registration form, to register here or read more information about the registration process. If you are already registered, please login here.

One zone not working correctly

I have one zone that is not working in my front yard. When turned on by the timer, the value is opened but does not get much pressure. If I open the bleed screw the system comes on correctly. The one thing that I did notice when looking through all the posts was that the height of the valve (anti-syphon type) needs to be 12 inches above the highest sprinkler. Unfortunately it is not. Would that cause a lack of pressure? or do I have a leak I need to find?

The diaphragm's bad. Depending which valve you have you can replace the diaphragm or changing the valve adapter is sometimes a better option. Plastic change the adapter. They're cheap enough. With brass if the valve isn't super old they sell rebuild kits or you can just change it.

A failed diaphragm assembly could leave some pieces in the pipe. Odds are good that it's the 100232-H assembly, and that a plastic piece broke away. Flush the valve once you have the top off. If all the heads on a zone are located higher than the antisyphon valve feeding them, you have no backflow protection.

Thanks for the help. It was the diaphram, I replaced it last night (if I recall it was the RJ711) and they had the diaphram at OSH (local hardware store). What threw me was that both of the valves that I tried had bad diaphrams.